Assessment of tumourigenic potential in long-term cryopreserved human adipose-derived stem cells

Abstract

Cryopreservation represents an efficient way to preserve human mesenchymal stem cells (hMSCs) at early culture/passage, and allows pooling of cells to achieve sufficient cells required for off-the-shelf use in clinical applications, e.g. cell-based therapies and regenerative medicine. To fully apply cryopreserved hMSCs in a clinical setting, it is necessary to evaluate their biosafety, e.g. chromosomal abnormality and tumourigenic potential. To date, many studies have demonstrated that cryopreserved hMSCs display no chromosomal abnormalities. However, the tumourigenic potential of cryopreserved hMSCs has not yet been evaluated. In the present study, we cryopreserved human adipose-derived mesenchymal stem cells (hASCs) for 3 months, using a slow freezing method with various cryoprotective agents (CPAs), followed by assessment of the tumourigenic potential of the cryopreserved hASCs after thawing and subculture. We found that long-term cryopreserved hASCs maintained normal levels of the tumour suppressor markers p53, p21, p16 and pRb, hTERT, telomerase activity and telomere length. Further, we did not observe significant DNA damage or signs of p53 mutation in cryopreserved hASCs. Our findings suggest that long-term cryopreserved hASCs are at low risk of tumourigenesis. These findings aid in establishing the biosafety profile of cryopreserved hASCs, and thus establishing low hazardous risk perception with the use of long-term cryopreserved hASCs for future clinical applications. Copyright © 2016 John Wiley & Sons, Ltd.

Differential osteogenic potential of human adipose‐derived stem cells co‐cultured with human osteoblasts on polymeric microfiber scaffolds

“…Cell phenotyping for HADSCs was done through microscopic examination to confirm the morphology of fibroblastic‐like cells, cell plasticity, and cell stem adherence properties from passage 0 until passage 4 prior to cell seeding. The immunophenotyping study was previously reported, confirming that HADSCs retained stem cell characteristics after cultured expansion to passage 4 prior to cell seeding.…”

Cryopreserved Mesenchymal Stromal Cells Maintain Potency in a Retinal Ischemia/Reperfusion Injury Model: Toward an off-the-shelf Therapy

“…To date, studies focused on the impact of cryopreservation on MSC function have yielded mixed results 24 . Cryopreservation of MSC has become routine and MSC stored for extended periods of time have been shown to have low tumourigenic potential 25 , maintain growth kinetics upon thawing 26 , and remain capable of multilineage differentiation 26 27 28 29 . When MSC were examined for their ability to differentiate to form bone, cryopreservation did not significantly impact the differentiation capacity of the cells in in vitro assays 26 or after in vivo transplantation 27 28 29 .…”

Paracrine Effects of Adipose-Derived Stem Cells on Matrix Stiffness-Induced Cardiac Myofibroblast Differentiation via Angiotensin II Type 1 Receptor and Smad7

“…Human adipose tissues were obtained from female donors (25–35 years old) undergoing caesarean section with prior written informed consent. Isolation of hASCs was performed conform the declaration of Helsinki using protocols as described elsewhere 59 60 61 62 . In brief, human adipose tissues were washed, minced and digested using 0.3% collagenase type I (MP Biomedicals, Aurora, Ohio) solution at 37 °C with agitation.…”